Shy Hamlet

Hypoplectrus (Hamlets) are a colorful and relatively small predatory fish which are well suited to tank life. 
All the species are very alike, when not taking color and habitat into account. 

They will eat small fish and crustaceans which can be swallowed, but are otherwise not a threat to the other animals in the aquarium. 

Hamlets are fairly hardy and easy fish, but are not very good at adjusting to tank life. They should therefore be bought as young as feasible, and should be moved around as little as possible. 
They are easy to feed and do not require live food, so a varied diet of frozen fish, crustaceans and the like is sufficient. 
Needs to be fed once a day.